THE THEORY AND PRACTICE OF WORKING PLANS 39 



of orientation and silvicultural operation. It is a permanent sub- 

 division. It may or may not coincide with the pubHc land sur- 

 vey. There may be an indefinite number of compartments in a 

 block. The limits of a compartment are rectilinear in the plains 

 and follow topographic features in hill and mountain country. 

 The area of a compartment varies with the intensity of manage- 

 ment and seldom exceeds 500 acres.* In a forest under com- 

 plete management, the compartment boundaries are shown on 

 the, forest maps and are permanently marked on the ground 

 by blazed lines, durable monuments, posting, roads, trails, 

 streams or other well-defined natural features. 



The compartment is created for purposes of easier orienta- 

 tion in the woods and for facilitating and systematizing the keep- 

 ing of detailed forest records. Where the boundaries of com- 

 partments are hewn out or made into roads, these serve the addi- 

 tional purposes of fire lines, logging roads, points of attack in 

 cutting series, and as convenient units where game is beaten 

 from cover. t 



The Forest Service apparently favors the use of chance or 

 logging chance in place of compartment. This is a term in 

 common local use, more or less synonymous with logging 

 unit. It is not favored as a term in forest management. 



Lot or Subcompartment. — A permanent or temporary sub- 

 division of the compartment based upon differences in stand, 

 necessitating a different method of silvicultural treatment. 

 An example of permanent subdivision is the case of swamp in 

 the midst of pine land. An example of temporary subdivision 

 is the case of a severe burn in the midst of uninjured, mature 

 forest. 



Designation of Divisions. — Working units and blocks are 

 given names: compartments are numbered; subcompartments 



* Roth: " Forest Regulation," p. 38, says: " It is feasible even in high moun- 

 tain districts to stay below 200 acres in the average size of the lot." 



t Hence in the plains, e.g., in the Prussian pineries, the compartment is called 

 a " Jagen " i.e., a " hunting." The average size in Prussia is 25 hectares = 6i j 

 acres. 



